The present invention relates to a board-to-board electrical connector, and particularly to an electrical connector for signal transmission between different circuit boards.
U.S. Pat. Nos. 5,277,597, and Taiwan Patent Application Nos. 86202873, 86206353 each disclose a conventional board-to-board-to-board electrical connector. Referring to FIGS. 1A and 1B, a conventional board-to-board electrical connector 3 comprises an insulative housing 4 and a plurality of terminals 5. The insulative housing 4 includes a pair of side walls 41, 42 which are parallel to each other. A central portion 43 is disposed between the side walls 41, 42. A plurality of passageways 46 is exposed on opposite surfaces of the central portion 43 and the passageways 46 are equally distanced from each other by spacing boards (not shown). The terminals 5 are received in corresponding passageways 46 and each terminal 5 comprises a fixing portion 51, a contacting portion 52 and a soldering portion 53. The contacting portion 52 and the soldering portion 53 are respectively formed at opposite ends of the fixing portion 51. After the terminal 5 is assembled in the insulative housing 4, the soldering portion 53 is folded with right angle to solder on a circuit board (not shown). A plurality of barbs 55 is formed on opposites edges for engaging with the spacing boards for securing in the insulative housing 4.
However, the terminals 5 are assembled to the insulative housing 4 just through engagement between the barbs 55 and the spacing boards. This engagement is not reliable while an external force is exerted on the soldering portion 53 of each terminal 5. Under the external force the terminals 5 will be buckled inwardly. Furthermore, the soldering portion 53 is folded after the terminals 5 assembled to the insulative housing 4, thus, an additional tool is needed and planarity of the soldering portions 53 can not be properly controlled either.